Re: [Xen-devel] RE: [PATCH 2/7] x86, acpi, tboot: Have a ACPI sleep override instead of calling tboot_sleep.

[Jeremy Fitzhardinge <jeremy@goop.org>]

On 09/06/2011 09:20 PM, Cihula, Joseph wrote:
>> From: Konrad Rzeszutek Wilk [mailto:konrad.wilk@oracle.com]
>> Sent: Wednesday, August 31, 2011 11:31 AM
>>
>> The ACPI suspend path makes a call to tboot_sleep right before it writes the PM1A, PM1B values. We
>> replace the direct call to tboot via an registration callback similar to __acpi_register_gsi.
>>
>> CC: Thomas Gleixner <tglx@linutronix.de>
>> CC: "H. Peter Anvin" <hpa@zytor.com>
>> CC: x86@kernel.org
>> CC: Len Brown <len.brown@intel.com>
>> CC: Joseph Cihula <joseph.cihula@intel.com>
>> CC: Shane Wang <shane.wang@intel.com>
>> CC: xen-devel@lists.xensource.com
>> CC: linux-pm@lists.linux-foundation.org
>> CC: tboot-devel@lists.sourceforge.net
>> CC: linux-acpi@vger.kernel.org
>> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
>> ---
>>  arch/x86/include/asm/acpi.h   |    3 +++
>>  arch/x86/kernel/acpi/boot.c   |    3 +++
>>  arch/x86/kernel/tboot.c       |   13 +++++++++----
>>  drivers/acpi/acpica/hwsleep.c |   12 ++++++++++--
>>  include/linux/tboot.h         |    3 ++-
>>  5 files changed, 27 insertions(+), 7 deletions(-)
>>
>> diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h index 610001d..49864a1
>> 100644
>> --- a/arch/x86/include/asm/acpi.h
>> +++ b/arch/x86/include/asm/acpi.h
>> @@ -98,6 +98,9 @@ void acpi_pic_sci_set_trigger(unsigned int, u16);  extern int
>> (*__acpi_register_gsi)(struct device *dev, u32 gsi,
>>  				  int trigger, int polarity);
>>
>> +extern int (*__acpi_override_sleep)(u8 sleep_state, u32 pm1a_ctrl,
>> +				    u32 pm1b_ctrl, bool *skip_rest);
>> +
>>  static inline void disable_acpi(void)
>>  {
>>  	acpi_disabled = 1;
>> diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index 4558f0d..d191b4c
>> 100644
>> --- a/arch/x86/kernel/acpi/boot.c
>> +++ b/arch/x86/kernel/acpi/boot.c
>> @@ -552,6 +552,9 @@ static int acpi_register_gsi_ioapic(struct device *dev, u32 gsi,  int
>> (*__acpi_register_gsi)(struct device *dev, u32 gsi,
>>  			   int trigger, int polarity) = acpi_register_gsi_pic;
>>
>> +int (*__acpi_override_sleep)(u8 sleep_state, u32 pm1a_ctrl,
>> +			     u32 pm1b_ctrl, bool *skip_rest) = NULL;
>> +
>>  /*
>>   * success: return IRQ number (>=0)
>>   * failure: return < 0
>> diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c index 30ac65d..a18070c 100644
>> --- a/arch/x86/kernel/tboot.c
>> +++ b/arch/x86/kernel/tboot.c
>> @@ -41,7 +41,7 @@
>>  #include <asm/setup.h>
>>  #include <asm/e820.h>
>>  #include <asm/io.h>
>> -
>> +#include <linux/acpi.h>
>>  #include "acpi/realmode/wakeup.h"
>>
>>  /* Global pointer to shared data; NULL means no measured launch. */ @@ -270,7 +270,8 @@ static
>> void tboot_copy_fadt(const struct acpi_table_fadt *fadt)
>>  		offsetof(struct acpi_table_facs, firmware_waking_vector);  }
>>
>> -void tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control)
>> +int tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control,
>> +		 bool *skip_rest)
> Don't you need to use the 'unused' attrib on skip_rest in order to prevent compiler warnings?

No, gcc doesn't warn about unused parameters.

    J